POLCONIC
Polar mode plot of general conics
----begin documentation----
Program:  POLCONIC
Author:   John P. Powers (jpp@cpdvax.csc.ti.com)
Date:     December 1992

Given the coefficients of a general conic

    Ax^2 + Bxy + Cy^2 + Dx + Ey + F = 0

this program sketches the conic on the graph screen.

Once the program has been run, the user may store different
coefficients to variables A through F and change the graph range
settings on the RANGE screen.  Press [GRAPH] <GRAPH> to sketch the
new conic.

This program uses dot mode of the grapher to draw conics.  The user
may change the number of dots (N) in the graph by setting thetaStep
on the RANGE screen to 360/N.  This program initializes thetaStep to
9 degrees to draw forty points.

Example:  To plot the conic 16x^2 + 25y^2 - 160x - 200y + 400 = 0

POLCONIC [ENTER]
A=?16
B=?0
C=?25
D=?-160
E=?-200
F=400

An ellipse is drawn in the first quadrant.  Press [F5] (QUIT) to
terminate the program.

Change the coefficient of x^2 to 25 and regraph.

25->A [ENTER]
[GRAPH] <GRAPH>

A circle is now drawn in the first quadrant.
----end documentation----
----begin ascii----
\START\
\COMMENT=Polar mode graph of conics                
\NAME=POLCONIC
\FILE=polconic.85P
Pol
Degree
DrawDot
FnOff 
0\->\\@Min\:360\->\\@Max\:360/40\->\\@Step\
\(-)\17\->\xMin:17\->\xMax:1\->\xScl
\(-)\10\->\yMin:10\->\yMax:1\->\yScl
G=D cos \LC-theta\+E sin \LC-theta\
H=A (cos \LC-theta\)\^2\+B cos \LC-theta\ sin \LC-theta\+C(sin \LC-theta\\#\
)\^2\
r1=(\sqrt\(G\^2\/H\^2\-4F/H)-G/H)/2
Lbl AGAIN
Prompt  A,B,C,D,E,F
DispG 
Menu(1,"AGAIN",AGAIN,5,"QUIT",QUIT)
Lbl QUIT
\STOP\
----end ascii----
----begin uue----
begin 644 polconic.85p
M*BI423@U*BH:#`!0;VQA<B!M;V1E(&=R87!H(&]F(&-O;FEC<R`@("`@("`@
M("`@("`@("`*`0P`^@`2"%!/3$-/3DE#^@#X`&1O5V]Y;Y%O1#``"ST/;D0S
M-C``"ST0;D0S-C``<40T,``+/0MOH40Q-P`+/01N1#$W``L]!6Y$,0`+/0)O
MH40Q,``+/09N1#$P``L]!VY$,0`+/0-O,T<_,T2L,@'!8#-%JC(!P6\S2#\S
M01"L,@'!$4I@,T*L,@'!JC(!P6`S0Q"J,@'!$4IO.P)R,3\0H!`S1TIQ,TA*
M840T`#-&<3-($6$S1W$S2!%Q1#(`;^!!1T%)3@!OYS-!+S-"+S-#+S-$+S-%
M+S-&;^IO3!!$,0`O+4%'04E.`"\W04=!24XO1#4`+RU154E4`"\V455)5!%O
(X%%5250`1T4`
`
end
----end uue----